Simulated calcification clusters were extracted from unprocessed digital images of sliced mastectomy samples
(average thickness 5 mm) from seven patients acquired at 5 magnification (effective pixel size of 10 lm) on a digital
x-ray specimen cabinet (Model No. MX 20 DC2 Faxitron Bioptics, LLC, Lincolnshire, IL). All clusters used were
from malignant lesions. The method used for calcification cluster simulation was a slightly modified version of that
used previously, which is described extensively. Therefore, this text concentrates mainly on the differences of
this method from that used previously.